Garafa's GPSKit for iPhone provides you with more advanced GPS functionality and tracking for your iPhone:

• Dashboard - see real time information (speed, direction, coordinates, etc)
• Tracks - save your path, view in Google Earth or Maps
• Waypoints - Save points of interest

While GPSKit's solution is $9.99, there are other applications on the App Store that provide portions of similar functionality:

• GPS Tracker - real-time tracking service
• Speed - real time speedometer
• PathTracker - real time stats, save your path, also for runners/bikers
• Speedster GPS - speed and altitude in real time
• gpsCompass - real time stats
• Distance Meter - distance tracker
• iTrail - distance and path tracker for runners/bikers
• RunKeeper - track running/biking paths and stats

via iphone-chat